Great place to visit, Bangkok for a few days is enough though. Went there and onto Koh Samui for my honeymoon and thoroughly recommend Koh Samui it is beautiful but worth staying away from the main tourist area- Chaweng I think it was called. Food is unreal but immerse yourself into the culture to get the most from it. Haggle hard, hard, hard to get quality fakes etc at really low prices.
Ye I've bn to koh samui a couple of time with the ex Mrs, nice place, nice beaches, shops, hire a car and drive the island in a couple of hours, drive on the left too. Food is and still quite cheap there. You got to go see the this boxing tournaments that are advertised.